The present invention relates generally to furniture, and more particularly to an adjustable work surface for supporting a computer keyboard, monitor, mouse, digitizer board, joy stick or like accessories in a computer workstation.
Computer workstations are designed to be attractive and to provide an ergonomic interface with the computer operator for maintaining optimum proficiency over prolonged intervals of time without fatigue or physical discomfort. The workstation typically includes a monitor positioned on a shelf within an open console for viewing above, at or below the operator's eye level, and a keyboard located in front of the monitor on a separate shelf. The heights of the shelves from the floor, may be made adjustable by interengaging the ends of the shelves with vertically aligned fittings spaced vertically from one another at intervals on the interior sides of the console.
The keyboard height is especially critical. During keying, the operator's wrists should remain in a neutral position--not bent up, down or sideways--to reduce discomfort from unnecessary wrist stress. Improper wrist position over a prolonged period may increase risk of repetitive strain injury, a common form of mononeuropathy referred to as carpal tunnel syndrome. Therefore, the anthropometric parameters of the operators are important design criteria for workstations in general, and for keyboard shelf height in particular. ANSI/HFS 100-1988 Standards for Independent Keyboard Surfaces, Independent Display Surfaces and Clearance Under Work Surfaces, for example, require a minimum surface height from the floor of 23 inches for the 5th percentile female (approximately 5'0" tall) and 28 inches for the 95th percentile male (approximately 6'2" tall). However, the keyboard shelf should be adjustable within a range of greater heights to accommodate shorter and taller operators, as well as or the unique personal preferences of operators between the 5th and 95th percentiles.
Another feature often desired in computer consoles is a horizontally slidable keyboard shelf which can be completely retracted into the console when it is not in use. However, such keyboard shelves cannot be easily adjusted vertically. This is because the tracks in which the ends of the shelf move are permanently attached to the interior sides of the console. To reposition the keyboard to another height from the floor, the shelf must be removed from the tracks in order to allow access to the means fastening the guides to the console. This is time-consuming and often impractical, especially when several operators, short and tall, share the same workstation. Instead, the operators might forego adjusting the height and unwittingly expose themselves to the insidious consequences of wrist strain.
Accordingly, it is an object of the present invention to provide, in a computer workstation, a work surface for a keyboard and like control accessories which can be ergonomically adjusted in height to alleviate discomfort from unnecessary wrist stress to the operator.
Another object is to provide, in a console, a horizontally extendible work surface which can be quickly and easily adjusted, within a range of heights, to suit the physical comfort and unique preferences of users.
Still another object is to provide a work surface which is horizontally slidable between supporting sides of a workstation, and the height of which can be easily adjusted.
A still further object is to provide a horizontally slidable work surface which can be changed from a horizontal position to a forwardly or rearwardly slanted position.
Still another object is to provide a work surface for a workstation which is simple to adjust in height and slant, which is completely retractable, and which can securely support a computer keyboard and other items employed by an operator.
Briefly, these and other objects and aspects of the invention are accomplished by a workstation having the following construction. A supporting surface is provided, having opposite edge, each edge having a track-engaging slide. A pair of tracks is provided, the tracks being located alongside the opposite edges of the supporting surface and slidably receiving the track-engaging slides to permit sliding of the supporting surface in a path defined by the tracks. Each of the tracks has front and rear projections for engaging a supporting slot. First and second plate means are provided. The first plate means is located alongside one of the opposite edges of the supporting surface, and the second plate means is located alongside the other of the opposite edges of the supporting surface. Each of the first and second plate means is supported at a predetermined height. The first plate means has a front supporting slot receiving the front projection of one of the tracks and a rear supporting slot receiving the rear projection of the same track. The second plate means has a front supporting slot receiving the front projection of the other track and a rear supporting slot receiving the rear projection of the same track. One of the slots in each plate means comprises a vertically elongated section having a plurality of notches extending therefrom, at vertically spaced locations, in a direction transverse to the direction of elongation of the slot, for receiving one of the projections. The other of the slots in each plate means also comprises a vertically elongated section having a plurality of notches extending therefrom, at vertically spaced locations. Each of the latter notches extends transverse to the direction of elongation of said other of the slots and has a downwardly extending pocket formed therein and spaced from the vertically elongated section, for receiving another one of the projections. With this structure, for vertical adjustment of the position of the supporting surface, the track-providing means must be moved upward, and then horizontally, to position the projections in the vertically elongated sections of the slots.
Further objects, advantages and details of the invention will become apparent from the following detailed description when read in conjunction with the drawings.